Combines are large self-propelled vehicles used for harvesting and threshing agricultural crop in the field. A harvesting head is typically disposed across the front of the combine vehicle supported on a feederhouse. This harvesting head is configured to cut and convey the crop into the combine vehicle itself where it is threshed, separated, and cleaned.
Traditional harvesting heads included an elongate rigid frame to which harvesting implements are added such as row units, reciprocating knife assemblies, augers, reels, and endless belt conveyors. One such type of harvesting head is called a “draper platform” or “draper”.
Draper platforms have an elongate frame on which are mounted left and right side endless belt conveyors mounted immediately behind a reciprocating knife. These endless conveyors convey cut crop material inward to a center portion of the draper platform, depositing them on a center conveyor that moves rearward. The center conveyor carries the material to and through an aperture at the rear of the draper platform frame, where it is deposited in an elevating conveyor called a feederhouse, which carries the cut crop material into the combine vehicle for threshing, separating and cleaning.
In one arrangement, the reciprocating knife is mounted on pivoting support arms that extend forward from a rear transverse frame member. See US 2009/0249760 A1, FIGS. 1-11, in which the conveyors are stationary and the reciprocating knife moves up and down on parallelogram arms. This arrangement permits the entire cutter bar to flex up and down, severing the crop plants close to the ground.
In another arrangement, the left and right side conveyors have also been mounted on pivoting support arms. These support arms are generally horizontal and are pivotally connected to an elongate laterally extending frame member at their rear ends, and are connected to and support a reciprocating knife at their front ends. The pivoting arms permit both the conveyor belts and the reciprocating knife to move up and down to follow the terrain.
For example, in US 2009/0249760 A1 a second embodiment is illustrated in FIGS. 12-22 in which the rear center conveyor roller is fixed with respect to the rear beam and supports two side plates that support the forward roller and are connected by a pan extending underneath the endless belt that is connected to skids via a sliding connection. The side conveyor belts are supported on arms disposed above the center conveyor that pivot up and down.
US 2009/0084080 discloses another arrangement in which the side conveyors are supported on pivoting arms. No center conveyor is disclosed, however.
US 2010/0011729 illustrates a center conveyor supported on a frame that also supports a feeder drum. Side plates support the front and rear rollers of the center conveyor and the forward end of the conveyor is received and supported in V-shaped guides that extend rearward from the reciprocating knife assembly of the draper platform. The system is arranged to permit the feeder drum and center conveyor to be slidably inserted into and removed from the draper platform from the rear of the platform.
The problem to be solved is that of supporting the center conveyor between two floating arms to permit the arms supporting the reciprocating knife and disposed on each side of the center conveyor to pivot up and down, thereby permitting the reciprocating knife to follow the contours of the ground more accurately.
This problem is solved by the arrangement described in claim 1. Further advantages are provided by additional claims that are dependent upon claim 1.